/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.service.thrift.handler;

import org.apache.iotdb.db.query.control.SessionManager;
import org.apache.iotdb.db.query.control.clientsession.ClientSession;
import org.apache.iotdb.external.api.thrift.JudgableServerContext;
import org.apache.iotdb.external.api.thrift.ServerContextFactory;
import org.apache.iotdb.rpc.TElasticFramedTransport;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.server.ServerContext;
import org.apache.thrift.transport.TSocket;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.Socket;
import java.util.ServiceLoader;

public class BaseServerContextHandler {
    private static ServerContextFactory factory = null;
    private static final Logger logger = LoggerFactory.getLogger(BaseServerContextHandler.class);

    static {
        ServiceLoader<ServerContextFactory> contextFactoryLoader =
                ServiceLoader.load(ServerContextFactory.class);
        for (ServerContextFactory loader : contextFactoryLoader) {
            if (factory != null) {
                // it means there is more than one implementation.
                logger.warn("There are more than one ServerContextFactory implementation. pls check.");
            }
            logger.info("Will set ServerContextFactory from {} ", loader.getClass().getName());
            factory = loader;
        }
    }

    public BaseServerContextHandler() {
    }

    public ServerContext createContext(TProtocol in, TProtocol out) {
        Socket socket =
                ((TSocket) ((TElasticFramedTransport) out.getTransport()).getSocket()).getSocket();
        JudgableServerContext context = null;
        getSessionManager().registerSession(new ClientSession(socket));
        if (factory != null) {
            context = factory.newServerContext(out, socket);
            if (!context.whenConnect()) {
                return context;
            }
        }
        return context;
    }

    public void deleteContext(ServerContext context, TProtocol in, TProtocol out) {
        getSessionManager().removeCurrSession();
        if (context != null && factory != null) {
            ((JudgableServerContext) context).whenDisconnect();
        }
    }

    protected SessionManager getSessionManager() {
        return SessionManager.getInstance();
    }
}
